Checking Brake Discs For Edge Damage

Information 

• Irrespective of wear, a brake disc change may be necessary due to edge damage on the brake disc friction surfaces. 
• In such cases, only one brake disc may need to be replaced if the friction surface of the other PCCB brake disc is still perfectly OK. 
  Fig 1: Locating Edge Damage On PCCB Brake Disc

  Courtesy of PORSCHE CARS NORTH AMERICA, INC.

• Max. permissible width/depth = 2 mm (0.08 inches)
• Max. permitted length = 10 mm (0.39 inches)
• Max. 3 damaged edge areas permissible